Display substrate capable of decreasing defects and the method of the same

Abstract

According to an exemplary embodiment, a display substrate includes a gate metal pattern comprising a gate electrode, an active pattern disposed on the gate pattern and a source metal pattern disposed on the active pattern. The source metal pattern includes a first lower pattern disposed on the active pattern, a second lower pattern disposed on the first lower pattern, a low-resistance metal pattern disposed on the second lower pattern, and an upper pattern disposed on the low-resistance metal pattern. The first lower pattern, the second lower pattern, and the upper pattern each include a material that is the same.

What is claimed is: 
     
       1. A method of manufacturing a display substrate comprising:
 forming a gate metal pattern including a gate electrode on a base substrate; 
 forming a gate insulation layer that covers the gate metal pattern; 
 forming an active layer on the gate insulation layer; 
 forming a source metal layer on the active layer; 
 forming a photoresist layer on the source metal layer; 
 developing the photoresist layer to form a first photoresist pattern; and 
 forming an active pattern and a source metal pattern by etching the active layer and the source metal layer while using the first photoresist pattern as a mask,
 wherein forming the source metal layer comprises:
 depositing a first lower layer comprising molybdenum or molybdenum alloy on the active layer; 
 depositing a third lower layer comprising molybdenum nitride; 
 depositing a second lower layer comprising molybdenum or molybdenum alloy on the third lower layer; 
 depositing a low-resistance metal layer comprising aluminum or aluminum alloy on the second lower layer; and 
 depositing an upper layer comprising molybdenum or molybdenum alloy on the low-resistance metal layer, and 
 
 wherein the source metal layer is etched by a fluorine-containing gas. 
 
 
     
     
       2. The method of  claim 1 , wherein forming the source metal layer includes performing a plasma process on the first lower layer after the first lower layer is deposited. 
     
     
       3. The method of  claim 2 , wherein performing a plasma process on the first lower layer is performed by using a gas comprising nitrogen (N2). 
     
     
       4. The method of  claim 1 , wherein forming the source metal layer further comprises performing a plasma process on the second lower layer after the second lower layer is deposited. 
     
     
       5. The method of  claim 4 , wherein performing a plasma process on the first lower layer is performed by using a gas comprising nitrogen (N2). 
     
     
       6. The method of  claim 1 , wherein forming the active pattern and the source metal pattern comprises:
 wet-etching, using the first photoresist pattern as a first mask, the source metal layer; 
 removing a portion of the first photoresist pattern to form a second photoresist pattern that exposes a portion of the source metal layer; and 
 dry-etching, using the second photoresist pattern as a second mask, the active and the source metal layer to form the active pattern and the source metal pattern. 
 
     
     
       7. The method of  claim 1 , wherein the active pattern includes silicon. 
     
     
       8. The method of  claim 1 , further comprising forming an ohmic contact pattern on the active pattern. 
     
     
       9. The method of  claim 1 , further comprising forming a pixel electrode contacting the upper layer and including a transparent conductive material. 
     
     
       10. The method of  claim 1 , wherein the source metal pattern includes a source electrode, a drain electrode spaced apart from the source electrode and a data line electrically connected to the source electrode.